1. Field of the Invention
The present invention relates to an inkjet recording medium.
2. Description of the Related Art
With the improvement in resolution of images printed by recent inkjet printers, it has become possible to obtain recorded matter of photograph-like high quality, and with this evolution of the hardware (apparatus), various kinds of media for inkjet recording have been developed.
Properties required of recording sheets for inkjet recording generally include (1) a property of drying quickly (having a high ink absorption speed), (2) a property of ensuring ink dots of a correct and uniform diameter (being free of bleeding), (3) a property of ensuring good graininess, (4) a property of ensuring ink dots of high roundness, (5) a property of ensuring high color density, (6) a property of ensuring high color saturation (no dullness), (7) a property of ensuring high resistance to water, light and ozone in a printed portion, (8) a property of having a high degree of whiteness in the background portion, (9) a property of having good storability (a property of causing neither yellow coloration even over long-term storage nor bleeding of images by long-term storage (bleeding with aging)), (10) a property of having high resistance to deformation and good dimensional stability (having sufficiently limited curling), and (11) a property of ensuring smooth running in an apparatus.
When recording sheets are used as glazed photo paper for the purpose of obtaining photograph-like high-quality recorded matter, they are further required to have glossiness, surface smoothness and texture resembling that of photographic printing paper for silver-salt photographs, in addition to the properties recited above.
For the purpose of improving these properties, inkjet recording media having porous structures in their respective ink-receiving layers have been developed and put to practical use in recent years. Such inkjet recording media may have excellent ink receptivity (quick-dry properties) and high glossiness owing to their porous structures.
For example, inkjet recording media having, on or above a substrate, an ink-receiving layer containing fine particles of an inorganic pigment, a water-soluble resin, a multivalent metal salt, and an acetyleneglycol compound have been proposed (see, for example, JP-A No. 2003-326832). JP-A No. 2003-326832 discloses that these inkjet recording media have excellent resistance to bleeding, do not cause coating problems, and further have excellent resistance to bleeding during storage after printing.
However, the inkjet recording papers disclosed in JP-A No. 2003-326832 do not satisfactorily suppress bleeding after printing, especially in a high humidity environment.